The invention relates to an open-end friction spinning machine with a plurality of adjacently arranged spinning units which respectively include two adjacently arranged rollers driven in the same rotational direction and forming an accessible yarn forming wedge-shaped slot or gap. The open-end friction spinning machine is also provided with a fiber inlet and opening device for fiber material to be spun. A fiber feed channel extends from the inlet and opening device to a fiber feed opening opposite the wedge-shaped gap. A yarn withdrawal device is provided for drawing off the produced yarn in the longitudinal direction of the wedge-shaped gap.
The spinning machines of this type commonly known include a plurality of similarly operating, adjacently arranged spinning units disposed preferably on both sides of the machine. Open end friction spinning machines of this type are designed in accordance with similar basic principles whereby it is a practical demand to design the machine in such a manner that the wedge-shaped gaps formed by the adjacently arranged roller pairs of each spinning unit respectively are made accessible for maintenance purposes, for example, to examine the rollers after a yarn break and, if necessary, to eliminate the cause for the yarn break.
With a known apparatus or device having only one spinning unit as disclosed in published Unexamined European Pat. application (EP-OS) 52 412 it is provided that the wedge-shaped gap is only partially exposed. The fiber feed channel positioned with its opening opposite the wedge-shaped gap is stationarily positioned within a housing with known construction. One of the two rollers is movably borne so as to allow its relocation away from the fiber feed channel and the other roller. Thereby the wedge-shaped gap and a portion of the opening of the fiber feed channel is made accessible for an inspection and/or maintenance process. The accessibility not only to the wedge-shaped gap but also to the fiber feed channel is not very good with this arrangement. In addition to that, retention of the desired narrow tolerance in the site of the wedge-shaped gap between the two rollers is made essentially more difficult since one of the rollers is movably arranged. Such a device or arrangement was generally determined to be too expensive, and also inconvenient for a maintenance process, in order to be meaningfully used in a series machine.
The invention is based upon the problem to construct a spinning unit for an open end friction spinning machine which, on the one hand, can be efficiently maintained and, on the other hand, retains an exact arrangement of the most essential individual operating elements without making unnecessarily high demands on tolerances to be followed by the manufacturer.
This problem is thereby solved in accordance with the invention by providing that each of the spinning units includes a fiber feed channel carrier, movably arranged for exposing the wedge-shaped gap, which channel carrier forms at least one portion of the fiber feed channel extending between the fiber inlet and opening device and containing the fiber feed opening of the same wherein the fiber feed channel carrier while in operational position is adjustable by means of a centering means with respect to the inlet and opening device and also with respect to the bearing housing holding the two rollers. It is achieved with this arrangement of the invention that, on the one hand, the wedge-shaped gap is readily accessible by removing the channel carrier whereby not only the wedge-shaped gap, but also the opening of the fiber feed channel is made accessible for a maintenance procedure and especially for a cleaning procedure. With the arrangement of the invention the channel carrier is that constructional element of a spinning unit with respect to which the functionally essential elements are adjusted by means of the centering means, so that one can obtain the specified operational conditions at any time by returning the channel carrier to its operational position. The manufacture of the holders of these individual elements does not require a high tolerance level so that a series manufacture and the assembly of a series machine is made essentially easier. The channel carrier is the central element to which the other interacting elements are adjusted to when closing the spinning unit.
In order to remove the channel carrier without disturbing the operation of the neighboring spinning units, one preferred embodiment of the invention provides that the channel carrier is retained by a pivoting holder pivotable about an axis extending in the longitudinal direction of the machine. It is thereby especially advantageous according to certain preferred embodiments that the holder consists of a cover like element serving as a cover piece for each of the spinning units. The holder thereby has an additional function of serving as a covering for the machine parts.
In certain preferred embodiments of the invention it is provided that the channel carrier is detachably arranged at a center plate affixed to a holder in an adjusted position by means of a fitting connection. It is thereby possible to exchange the channel carrier with the channel element containing the fiber feed opening without making any other adjustments, in order to, for example, obtain more favorable spinning conditions for different fiber material to be spun.
In certain preferred embodiments of the invention, it is provided that the inlet and opening device includes a housing for the opening roller which is pivotable about an axis extending essentially perpendicular to the axis extending in the longitudinal direction of the machine. A drive wharve of the opening roller is thereby selectively detachable from the drive belt. The channel carrier in the operational position is disposed with a guide face engageable with a counterpart of the opening roller housing to hold the same against the force of a spring in the operational position of said opening roller housing. It can thereby be attained that the operation of the opening roller is interrupted when the spinning unit is opened and the wedge-shaped gap is exposed. Furthermore, by the choice of the swivel axles of the holder and the housing of the opening roller, it is assured that the force with which the housing of the opening roller is loaded out of its operational position has become effective with only a minor movement in the opening direction of the channel carrier.
In a further arrangement of preferred embodiments of the invention, it is provided that between the channel area and the bearing housing, centering means are arranged which adjust the distance of the opening of the fiber feed channel and the relative position of the same to the wedge-shaped gap. A high degree of accuracy in the adjustment of the two structural elements is thus assured.
In a still further arrangement of the invention it is provided that the bearing housing of each spinning unit is stationarily arranged at the machine frame by insertion of elastical spring means. It is thereby attained, that the rollers do not change their position when the spinning unit is opened so that they are well accessible for a cleaning procedure, especially for procedures utilizing an automatic cleaning device. Further, it is facilitated that the bearing housing with the rollers is adjusted to a very minor degree against the channel carrier. It is especially advantageous if in further features of the invention, the bearing housing of each spinning unit is supported at the machine frame by means of one or several rubber elastic blocks. Thereby, not only the possibility of adjustment in each of the possible degrees of freedom is facilitated, but also a vibration damping, and thereby also a noise damping is obtained.
According to further advantageous features of certain preferred embodiments of the invention it is provided that the bearing housing is positioned upon screw bolts of the machine frame by means of keyhole-like recesses. It is thereby possible to dismantle the bearing housing as a whole together with the respective rollers, if such becomes necessary.
According to yet another preferred advantageous feature of certain preferred embodiments of the invention, it is provided that the operational position of the channel carrier is secured by means of a detachable locking device. It is thereby achieved that the channel carrier always remains in the same operational position so that all other interacting and cooperating additional structural elements will remain in the same position.
According to another feature of the invention it is provided that the locking device includes a control lever connected to a device for interrupting the drive of the rollers and/or for braking the rollers. It is thereby attained that when opening the locking device in order to provide access to the spinning unit, the drive of the rollers is interrupted or the rollers are braked so that any danger of injury to the servicing person by the exposed rollers is avoided.
Further objects, features, and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawings which show, for purposes of illustration only, embodiments in accordance with the present invention.